<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>
    //1. let 具有块级作用域
    {
        let a = 1
        console.log("a = " + a)
    }
    // console.log(a)

    //2. let 声明的变量不能重复声明
    // let a = 1
    // let a = 2

    //3. let 声明的变量不能提升
    // console.log(a)
    // let a = 1

</script>

</body>
</html>
